1. Field of the Invention
The present invention relates to a vent structure and a method of manufacturing the vent structure.
2. Description of Related Art
A vent member is installed in a housing for accommodating electrical components of an automobile, such as lamps, sensors, and an ECU. Such a vent member is intended to ensure the ventilation between the interior and the exterior of the housing and to block the entry of foreign substances into the housing. An example of such a vent member is disclosed in JP 2004-47425 A.
A vent member disclosed in JP 2004-47425 A includes a supporting body 103, a gas-permeable membrane 102 disposed on the supporting member 103, and a protecting portion 104 fitted in the supporting member 103 to cover the gas-permeable membrane 102, as shown in FIG. 11. Such a vent member 101 is fixed to an opening portion 107 of a housing 106 with an O-ring 105. A gas passes through the gas-permeable membrane 102, which ensures the ventilation between the interior and the exterior of the housing 106. The protecting portion 104 prevents the gas-permeable membrane 102 from being damaged by external force (for example, a water jet used for car washing) or from having decreased gas permeability due to the accumulation of dust.